Calculate whiteout duration on linux (the time we draw green

or white because of no backing store).  This is mainly just
a copy of the Windows code (mac has it too).

Review URL: http://codereview.chromium.org/220043

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@27195 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 17 insertions, 0 deletions

diff --git a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
index 56b64ad..0f680bc 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
@@ -571,9 +571,20 @@ void RenderWidgetHostViewGtk::Paint(const gfx::Rect& damage_rect) {
       backing_store->ShowRect(
           paint_rect, x11_util::GetX11WindowFromGtkWidget(view_.get()));
     }
+    if (!whiteout_start_time_.is_null()) {
+      base::TimeDelta whiteout_duration = base::TimeTicks::Now() -
+          whiteout_start_time_;
+      UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration", whiteout_duration);
+
+      // Reset the start time to 0 so that we start recording again the next
+      // time the backing store is NULL...
+      whiteout_start_time_ = base::TimeTicks();
+    }
   } else {
     if (window)
       gdk_window_clear(window);
+    if (whiteout_start_time_.is_null())
+      whiteout_start_time_ = base::TimeTicks::Now();
   }
 }
 
diff --git a/chrome/browser/renderer_host/render_widget_host_view_gtk.h b/chrome/browser/renderer_host/render_widget_host_view_gtk.h
index 102eb09..2f7e6b3 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_gtk.h
+++ b/chrome/browser/renderer_host/render_widget_host_view_gtk.h
@@ -13,6 +13,7 @@
 
 #include "base/gfx/native_widget_types.h"
 #include "base/scoped_ptr.h"
+#include "base/time.h"
 #include "chrome/browser/renderer_host/render_widget_host_view.h"
 #include "chrome/common/owned_widget_gtk.h"
 #include "webkit/glue/plugins/gtk_plugin_container_manager.h"
@@ -113,6 +114,11 @@ class RenderWidgetHostViewGtk : public RenderWidgetHostView {
   // Whether we are showing a context menu.
   bool is_showing_context_menu_;
 
+  // The time at which this view started displaying white pixels as a result of
+  // not having anything to paint (empty backing store from renderer). This
+  // value returns true for is_null() if we are not recording whiteout times.
+  base::TimeTicks whiteout_start_time_;
+
   // Variables used only for popups --------------------------------------------
   // Our parent widget.
   RenderWidgetHostView* parent_host_view_;